DOCSLIB.ORG

Novel Peptides Derived from Αs1-Casein with Opioid Activity and Mucin Stimulatory Effect on HT29-MTX Cells

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Novel Peptides Derived from Αs1-Casein with Opioid Activity and Mucin Stimulatory Effect on HT29-MTX Cells CORE Metadata, citation and similar papers at core.ac.uk Provided by Digital.CSIC Novel peptides derived from αs1-casein with opioid activity and mucin stimulatory effect on HT29-MTX cells S. Fernández-Tomé1, D. Martínez-Maqueda1, R. Girón2, C. Goicoechea2, B. Miralles1, I. Recio1 1Instituto de Investigación en Ciencias de la Alimentación, CIAL (CSIC-UAM, CEI UAM+CSIC), Nicolás Cabrera, 9, 28049 Madrid, Spain. 2Farmacología y Nutrición, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Unidad Asociada al IQM y al CIAL del CSIC, Avda. Atenas, s/n, 28922 Alcorcón, Madrid, Spain 1 ABSTRACT 143 149 This study investigates the opioid effect of αs1-casein fragments related to AYFYPEL and 144YFYPEL149, which had previously shown mucin-stimulatory activity in human goblet cells. Peptides 144YFYPEL149 and 144YFYPE148 showed opioid agonistic activity in guinea pig ileum, and in mouse vas deferens but to a lower extent. Peptides were partly hydrolysed during the assay and several of the resulting fragments lost the N-terminal Tyr residue. Docking of peptides 144YFYPEL149 (active) and 144YFYP147 (inactive) into the active site of the opioid receptor model showed remarkable differences regarding the flexibility at the third intracellular loop of the receptor and the interaction with Pro at the peptide C-terminus that forced residues Arg148 and Glu166 from the receptor to move towards the interior of the binding pocket. The study on 144 149 human cells HT29-MTX has shown that αs1-casein YFYPEL is the minimum fragment able to stimulate MUC5AC expression. KEYWORDS: Opioid peptide; mu-opioid receptor; molecular dynamics; mucin; goblet cells HIGHLIGHTS: 144YFYPEL149 and 144YFYPE148 demonstrated opioid activity on guinea pig ileum 144YFYPEL149 and 144YFYP147 presented different behaviour against opioid receptor 144YFYPEL149 was the minimum fragment with stimulatory effect on MUC5AC expression 2 1. INTRODUCTION During food digestion, proteins render a large variety of different peptides. Some of these sequences are structurally similar to endogenous physiologically active peptides and therefore, these food-derived sequences can interact with the same receptors in the organism, exerting an agonist or antagonist activity. One of the best examples where this applies, are food-derived opioid peptides, i.e., exogenous opioid receptor ligands with agonistic activity. From milk, peptides derived from β-casein, referred as β-casomorphins, were the first food protein-derived opioid receptor ligands whose sequences were identified (Brantl, Teschemacher, Henschen, & Lottspeich, 1979). They have been found in in vivo digestion products from humans and minipigs (Barbé et al., 2014; Boutrou et al., 2013). The common structural characteristics of both, exogenous and endogenous opioid peptides, are the presence of a tyrosine residue at the N-terminus and the presence of other aromatic residue, phenylalanine or tyrosine, in the third or fourth position (Meisel, 1997). In case of the αs1- casein derived peptides or α-casein exorphins, the active sequence can contain an additional arginine residue at the N-terminus. Although caseins are source of many peptides showing agonist or antagonist action on different opioid receptors, opioid peptides from other protein sources have been also described, such as whey proteins (Antila et al., 1991) and hemoglobin (Zhao, Garreau, Sannier, & Piot, 1997) from animal sources and gluten, rice, or soy from plant proteins (Yoshikawa, 2015). Biological activities observed for these food-derived opioid sequences include analgesia and modulation of social behaviour, after parenteral or intracerebral administration to animals. Orally administered food-derived opioid peptides have demonstrated to influence postprandial metabolism by stimulating secretion of insulin and somatostatin, prolongation of gastrointestinal transit time, stimulation of food intake, and effects on the immune system, among others (for reviews regarding biological activity, see Meisel & FitzGerald, 2000; Rutherfurd-Markwick, 2012; Teschemacher, 2003; Teschemacher, Koch & Brantl, 1997). 3 Moreover, it was found that the opioid peptide β-casomorphin-7 (60YPFPGPI66) induced intestinal mucin release through a nervous pathway and opioid receptor activation in ex-vivo preparations of rat jejunum (Claustre et al., 2002; Trompette et al., 2003). In human (HT29- MTX) and rat (DHE) intestinal mucin-producing cells, this peptide increased secretion and expression of mucin, and these effects were prevented with the μ-opioid antagonist cyprodime (Zoghbi et al., 2006). Similar effects were reported for the μ-opioid ligands, α- lactorphin (Martínez-Maqueda et al., 2012) and β-lactorphin (Martínez-Maqueda, Miralles, Ramos, & Recio, 2013b). However, other β-casein-derived peptides whose structures do not fulfil the requirements of opioid ligands have also demonstrated regulation of mucin production in HT29-MTX cells and in animals, such as the peptide β-CN f(94-123) found in yogurts and the derived fragments (94-108) and (117-123) (Plaisancié et al., 2013; Plaisancié et al., 2015). Our group had shown the mucin secretory activity of various bovine αs1-casein-derived peptides with favourable structures to bind opioid receptors due to the presence of Tyr at the N-terminus or in the second position and other Tyr in the third or fourth position. From these peptides, fragments 143AYFYPEL149, 144YFYPEL149 and a casein hydrolysate containing both sequences produced an increased mucin secretion and MUC5AC gene expression in HT29-MTX cells (Martínez-Maqueda, Miralles, Cruz-Huerta, Recio, 2013a). Interestingly, these two peptides had been identified in in vivo gastric and duodenal human digests after milk ingestion (Chabance et al., 1998). However, despite the favourable structure of these sequences and their potential to interact with opioid receptors located at the intestinal tract, the opioid activity of these peptides has not been previously demonstrated. The objective of this work 143 149 was to investigate the opioid effect of the bovine αs1-casein fragment AYFYPEL , and four derived peptides comprising the core structure for opioid activity YFY in guinea pig ileum and mouse vas deferens preparations. A molecular docking of two peptides into the active site of the μ-opioid receptor was carried out to identify the key residues responsible for the affinity to 4 the receptor. In addition, a preliminary study of these sequences on MUC5AC gene overexpression in HT29-MTX cells is shown. 2. MATERIALS AND METHODS 2.1. Peptides 143 149 144 149 144 148 144 147 144 146 αs1-casein fragments AYFYPEL , YFYPEL , YFYPE , YFYP and YFY , and the β-casein fragment 60YPFPGPI66 were synthesized in house using conventional solid- phase FMOC synthesis with a 433A peptide synthesizer (Applied Biosystems, Warrington, UK). In the peptide purification protocol, the treatment with acetic acid was included to replace trifluoroacetic acid which affects the pH of the peptide solutions in the bioassays. Their purity (>90%) was verified in our laboratory by reverse phase high performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS). 2.2. Isolated preparations from guinea pig ileum and mouse vas deferens Female guinea-pigs weighing 300-450 g, and male CD-1 mice weighing 25-60 g were used. Myenteric plexus-longitudinal muscle strips (MP-LM) from guinea pig ileum, and the mouse vas deferens were isolated as described by Ambache (1954) and Hughes et al. (1975), respectively. Tissues were suspended in a 10 ml organ bath containing 5 ml of Krebs solution (NaCl 118, KCl 4.75, CaCl2 2.54, KH2PO4 1.19; MgSO4 1.2; NaHCO3 25; glucose 11mM). This solution was continuously gassed with 95% O2 and 5% CO2. Tissues were kept under 1 g (guinea pig ileum) or 0.5 g (mouse vas deferens) of resting tension, at 37 ºC and were electrically stimulated through two platinum ring electrodes. MP-LM strips were stimulated with rectangular pulses of 70 V, 0.1 ms duration and 0.3 Hz frequency, and mouse vas deferens with trains of 15 rectangular pulses of 70 V, 15 Hz and 2 ms duration each min. The isometric force was monitored by computer using a MacLab data recording and analysis system. In both 5 assays the interval between applications of increasing concentrations was optimized to obtain a stable signal, and it was 9 min for αs1-casein peptides, and 3 min when control opioid agonists were tested. To evaluate the opioid-agonistic activity of peptides in the guinea pig ileum, cumulative concentration-response curves with five doses in the range 6.1 × 10-8 – 1.0 × 10-5 M were constructed in a step by step manner as follows: after 15 min-stabilisation of MP- LM strips in organ bath, electrical stimulation was applied, and peptide´s effect on the electrically induced contractions was evaluated once the response reached a plateau. Morphine was used as µ-opioid agonist positive control. To corroborate that the inhibitory effect of the peptides was mediated through interaction with opioid receptors, one dose of naloxone (1.0 × 10-6 M, Sigma), an non-selective opioid antagonist, was added to the organ bath at the end of each experiment. In mouse vas deferens preparations, non-cumulative concentration-response curves with four doses in the range 5.5 × 10-7 – 1.0 × 10-5 M were tested. Once tissue stabilisation, the first peptide dose was added and evaluated. The tissue was then washed, and subsequent doses were applied. In this preparation, [D-Pen(2),D- Pen(5)]-enkephalin (DPDPE) was used as δ-opioid agonist, and one dose of naltrindole (1.0 × 10-9 - 1.0 × 10-7 M, Sigma), a δ-selective opioid antagonist, was added after the experiments to evaluate selective interaction with δ-opioid receptors. Results were expressed as % of inhibition, taking the mean amplitude of the last five contractions before the addition of the peptides as 100%. In guinea pig ileum, when the effect of peptidase inhibitors (captopril, amastatin and phosphoramidon 1.0 × 10-6 M, Sigma) was evaluated, they were added 5 min before the beginning of the peptide´s concentration-response curve (Akahori et al., 2008).
Load more

Recommended publications
  • Analytical Performance of an Immunoassay to Measure Proenkephalin ⁎ Leslie J
    Clinical Biochemistry xxx (xxxx) xxx–xxx Contents lists available at ScienceDirect Clinical Biochemistry journal homepage: www.elsevier.com/locate/clinbiochem Analytical performance of an immunoassay to measure proenkephalin ⁎ Leslie J. Donatoa, ,Jeffrey W. Meeusena, John C. Lieskea, Deborah Bergmannc, Andrea Sparwaßerc, Allan S. Jaffea,b a Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, United States b Division of Cardiology, Mayo Clinic, Rochester, MN 55905, United States c Sphingotec GmbH, Hennigsdorf, Germany ARTICLE INFO ABSTRACT Keywords: Background: Endogenous opioids, enkephalins, are known to increase with acute kidney injury. Since the mature Biomarkers pentapeptides are unstable, we evaluated the performance of an assay that measures proenkephalin 119–159 Proenkephalin (PENK), a stable peptide formed concomitantly with mature enkephalins. Enkephalin Methods: PENK assay performance was evaluated on two microtiterplate/chemiluminescence sandwich im- Pro-enkephalin munoassay formats that required 18 or 1 h incubation times. PENK concentration was measured in plasma from penKid healthy individuals to establish a reference interval and in patients with varied levels of kidney function and Assay validation comorbidities to assess the association with measured glomerular filtration rate (mGFR) using iothalamate clearance. Results: Assay performance characteristics in plasma were similar between the assay formats. Limit of quanti- tation was 26.0 pmol/L (CV = 20%) for the 1 h assay and 17.3 pmol/L (CV = 3%) for the 18 h assay. Measurable ranges were 26–1540 pmol/L (1 h assay) and 18–2300 pmol/L (18 h assay). PENK concentrations are stable in plasma stored ambient to 10 days, refrigerated to at least 15 days, and frozen to at least 90 days.
    [Show full text]
  • Casomorphins and Gliadorphins Have Diverse Systemic Effects Spanning Gut, Brain and Internal Organs
    International Journal of Environmental Research and Public Health Article Casomorphins and Gliadorphins Have Diverse Systemic Effects Spanning Gut, Brain and Internal Organs Keith Bernard Woodford Agri-Food Systems, Lincoln University, Lincoln 7674, New Zealand; [email protected] Abstract: Food-derived opioid peptides include digestive products derived from cereal and dairy diets. If these opioid peptides breach the intestinal barrier, typically linked to permeability and constrained biosynthesis of dipeptidyl peptidase-4 (DPP4), they can attach to opioid receptors. The widespread presence of opioid receptors spanning gut, brain, and internal organs is fundamental to the diverse and systemic effects of food-derived opioids, with effects being evidential across many health conditions. However, manifestation delays following low-intensity long-term exposure create major challenges for clinical trials. Accordingly, it has been easiest to demonstrate causal relationships in digestion-based research where some impacts occur rapidly. Within this environment, the role of the microbiome is evidential but challenging to further elucidate, with microbiome effects ranging across gut-condition indicators and modulators, and potentially as systemic causal factors. Elucidation requires a systemic framework that acknowledges that public-health effects of food- derived opioids are complex with varying genetic susceptibility and confounding factors, together with system-wide interactions and feedbacks. The specific role of the microbiome within
    [Show full text]
  • Epigenetic Effects of Casein-Derived Opioid Peptides in SH-SY5Y Human Neuroblastoma Cells Malav S
    Trivedi et al. Nutrition & Metabolism (2015) 12:54 DOI 10.1186/s12986-015-0050-1 RESEARCH Open Access Epigenetic effects of casein-derived opioid peptides in SH-SY5Y human neuroblastoma cells Malav S. Trivedi1*, Nathaniel W. Hodgson2, Stephen J. Walker3, Geert Trooskens4, Vineeth Nair1 and Richard C. Deth1 Abstract Background: Casein-free, gluten-free diets have been reported to mitigate some of the inflammatory gastrointestinal and behavioral traits associated with autism, but the mechanism for this palliative effect has not been elucidated. We recently showed that the opioid peptide beta-casomorphin-7, derived from bovine (bBCM7) milk, decreases cysteine uptake, lowers levels of the antioxidant glutathione (GSH) and decreases the methyl donor S-adenosylmethionine (SAM) in both Caco-2 human GI epithelial cells and SH-SY5Y human neuroblastoma cells. While human breast milk can also release a similar peptide (hBCM-7), the bBCM7 and hBCM-7 vary greatly in potency; as the bBCM-7 is highly potent and similar to morphine in it's effects. Since SAM is required for DNA methylation, we wanted to further investigate the epigenetic effects of these food-derived opioid peptides. In the current study the main objective was to characterize functional pathways and key genes responding to DNA methylation effects of food-derived opioid peptides. Methods: SH-SY5Y neuroblastoma cells were treated with 1 μM hBCM7 and bBCM7 and RNA and DNA were isolated after 4 h with or without treatment. Transcriptional changes were assessed using a microarray approach and CpG methylation status was analyzed at 450,000 CpG sites. Functional implications from both endpoints were evaluated via Ingenuity Pathway Analysis 4.0 and KEGG pathway analysis was performed to identify biological interactions between transcripts that were significantly altered at DNA methylation or transcriptional levels (p < 0.05, FDR <0.1).
    [Show full text]
  • Antitumor Activity of Actinonin in Vitro and in Vivo
    Vol. 4, 171-176, January 1998 Clinical Cancer Research 171 Antitumor Activity of Actinonin in Vitro and in Vivo Yang Xu, Lawrence T. Lai, Janice L. Gabrilove, 8), mye!oid and monocytic cells, and most myeloblastic leuke- and David A. Scheinberg’ mias as well as on cells and tissues outside the hematopoietic system including fibroblasts, intestinal epithelium, renal tubular Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York 10021 epithelium, and synaptic membranes of the central nervous system (I ). APN occurs as a homodimer, and the molecule is a 150-kDa, transmembrane glycoprotein with an intracellular ABSTRACT amino terminus (1). F23, an antihuman CD13/APN mAb, is able Actinonin, an antibiotic and CD13/aminopeptidase N to completely block the active site of the enzyme (9). (APN) inhibitor, has been shown to be cytotoxic to tumor Bestatin, a CD 1 3/APN inhibitor, was examined in preclin- cell lines in vitro. We investigated the antiproliferative ef- ical and clinical studies; bestatin could inhibit lymph node fects of actinonin on human and murine leukemia and lym- metastasis of P388 leukemia in mice (10) and was used in phoma cells. Actinonin inhibited growth of NB4 and HL6O clinical trials in malignant skin tumors (1 1), in head and neck human cell lines and AKR mouse leukemia cells in vitro with cancer (12), in esophageal cancer (13), and in gynecologic an IC50 of about 2-S g/ml. The inhibitory effect on CD13- tumors (14). High doses of bestatin resulted in the significant positive cells was not blocked by pretreatment with the inhibition of preexisting experimental and spontaneous metas- anti-CD13/APN monoclonal antibody F23, which binds with tasis in mice (15).
    [Show full text]
  • Nutritional Interventions for Autism Spectrum Disorder
    Lead Article Nutritional interventions for autism spectrum disorder Downloaded from https://academic.oup.com/nutritionreviews/advance-article-abstract/doi/10.1093/nutrit/nuz092/5687289 by Florida Atlantic University user on 06 January 2020 Elisa Karhu*, Ryan Zukerman*, Rebecca S. Eshraghi, Jeenu Mittal, Richard C. Deth, Ana M. Castejon, Malav Trivedi, Rahul Mittal, and Adrien A. Eshraghi Autism spectrum disorder (ASD) is an increasingly prevalent neurodevelopmental dis- order with considerable clinical heterogeneity. With no cure for the disorder, treat- ments commonly center around speech and behavioral therapies to improve the characteristic social, behavioral, and communicative symptoms of ASD. Gastrointestinal disturbances are commonly encountered comorbidities that are thought to be not only another symptom of ASD but to also play an active role in modulating the expression of social and behavioral symptoms. Therefore, nutritional interventions are used by a majority of those with ASD both with and without clinical supervision to alleviate gastrointestinal and behavioral symptoms. Despite a consider- able interest in dietary interventions, no consensus exists regarding optimal nutritional therapy. Thus, patients and physicians are left to choose from a myriad of dietary pro- tocols. This review, summarizes the state of the current clinical and experimental liter- ature on nutritional interventions for ASD, including gluten-free and casein-free, keto- genic, and specific carbohydrate diets, as well as probiotics, polyunsaturated fatty
    [Show full text]
  • Identifying the Inflammatory Pathways of Genes Upregulated in LADMAC Cells Exposed to BCM7 Oumlissa Persaud [email protected]
    Molloy College DigitalCommons@Molloy Biology Undergraduate Thesis Biology, Chemistry, and Environmental Science Fall 2017 Identifying the inflammatory pathways of genes upregulated in LADMAC cells exposed to BCM7 Oumlissa Persaud [email protected] Mary Kusenda Molloy College, [email protected] This research was completed as part of the degree requirements for the Biology Department at Molloy College. Follow this and additional works at: https://digitalcommons.molloy.edu/bio_ug_etd Part of the Biology Commons, and the Food Science Commons DigitalCommons@Molloy Feedback Recommended Citation Persaud, Oumlissa and Kusenda, Mary, "Identifying the inflammatory pathways of genes upregulated in LADMAC cells exposed to BCM7" (2017). Biology Undergraduate Thesis. 1. https://digitalcommons.molloy.edu/bio_ug_etd/1 This Thesis is brought to you for free and open access by the Biology, Chemistry, and Environmental Science at DigitalCommons@Molloy. It has been accepted for inclusion in Biology Undergraduate Thesis by an authorized administrator of DigitalCommons@Molloy. For more information, please contact [email protected],[email protected]. Biology, Chemistry, and Environmental Studies Department i The official copy of the thesis Identifying the inflammatory genes and pathways upregulated in LADMAC cells exposed to BCM7 A Thesis Presented by Oumlissa Persaud To The Undergraduate School in Partial Fulfillment of the Requirements for the Degree of Bachelors of Science Major in Biology at Molloy College 12/18/2017 ii Molloy College Biology, Chemistry and Environmental Studies Department Signature page I certify that I have read the thesis and that, in my humble opinion, I feel it successfully meets the requirements outlined by the thesis board in both scope and quality for the completion of the research track in biology at Molloy College.
    [Show full text]
  • Efficacy and Safety of Gluten-Free and Casein-Free Diets Proposed in Children Presenting with Pervasive Developmental Disorders (Autism and Related Syndromes)
    FRENCH FOOD SAFETY AGENCY Efficacy and safety of gluten-free and casein-free diets proposed in children presenting with pervasive developmental disorders (autism and related syndromes) April 2009 1 Chairmanship of the working group Professor Jean-Louis Bresson Scientific coordination Ms. Raphaëlle Ancellin and Ms. Sabine Houdart, under the direction of Professor Irène Margaritis 2 TABLE OF CONTENTS Table of contents ................................................................................................................... 3 Table of illustrations .............................................................................................................. 5 Composition of the working group ......................................................................................... 6 List of abbreviations .............................................................................................................. 7 1 Introduction .................................................................................................................... 8 1.1 Context of request ................................................................................................... 8 1.2 Autism: definition, origin, practical implications ........................................................ 8 1.2.1 Definition of autism and related disorders ......................................................... 8 1.2.2 Origins of autism .............................................................................................. 8 1.1.2.1 Neurobiological
    [Show full text]
  • (D-Ala*)Deltorphin II: D,-Dependent Stereotypies and Stimulation of Dopamine Release in the Nucleus Accumbens
    The Journal of Neuroscience, June 1991, 17(6): 1565-l 576 (D-Ala*)Deltorphin II: D,-dependent Stereotypies and Stimulation of Dopamine Release in the Nucleus Accumbens R. Longoni,’ L. Spina,’ A. Mulas,’ E. Carboni,’ L. Garau,’ P. Melchiorri,2 and G. Di Chiaral ‘Institute of Experimental Pharmacology and Toxicology, University of Cagliari, 09100 Cagliari, Italy and 21nstitute of Medical Pharmacology, University of Rome “La Sapienza,” 00185 Rome, Italy In order to investigate the relative role of central 6- and has been implicated in the stimulant actions of systemic opiates. F-opioid receptors in behavior, the effects of (D- Morphine-like opiates stimulate DA release preferentially in the Ala*)cleltorphin II, a natural Gopioid peptide, and PL017, nucleus accumbens (Di Chiara and Imperato, 1988a) and elicit a beta-casomorphin derivative specific for mu receptors, hypermotility sensitive to blockade by the DA D, receptor an- were compared after local intracerebral and intraventricular tagonist SCH 23390 (Longoni et al., 1987a). Intra-accumbens administration. lntracerebral infusion of the two peptides was infusion of opioid peptides elicits motor stimulation, but this done bilaterally in the limbic nucleus accumbens and in the action seems independent from DA, being resistant to classic ventral and dorsal caudate putamen of freely moving rats DA-receptor antagonists (neuroleptics; Pert and Sivit, 1977; Ka- through chronic intracerebral cannulas. After intra-accum- livas et al., 1983). Moreover, the syndrome elicited by intra- bens infusion, the two peptides elicited marked but opposite accumbens opiates is biphasic, as motor stimulation is typically behavioral effects: while (o-Ala2)deltorphin II evoked dose- preceded by motor inhibition and catalepsy (Costa11et al., 1978).
    [Show full text]
  • Enkephalin After Peptidase Inhibition
    J Pharmacol Sci 106, 295 – 300 (2008)2 Journal of Pharmacological Sciences ©2008 The Japanese Pharmacological Society Full Paper Great Increase in Antinociceptive Potency of [Leu5]Enkephalin After Peptidase Inhibition Kazuhito Akahori1, Kenya Kosaka1, Xing Lu Jin1, Yoshiharu Arai1, Masanobu Yoshikawa1, Hiroyuki Kobayashi1, and Tetsuo Oka1,* 1Department of Clinical Pharmacology, School of Medicine, Tokai University, Isehara 259-1143, Japan Received August 9, 2007; Accepted December 19, 2007 Abstract. Previous in vitro studies have shown that the degradation of [Leu5]enkephalin during incubation with cerebral membrane preparations is almost completely prevented by a mixture of three peptidase inhibitors: amastatin, captopril, and phosphoramidon. The present in vivo study shows that the inhibitory effect of [Leu5]enkephalin administered intra-third-ventricularly on the tail-flick response was increased more than 500-fold by the intra-third-ventricular pretreatment with the three peptidase inhibitors. The antinociceptive effect produced by the [Leu5]enkephalin in rats pretreated with any combination of two peptidase inhibitors was significantly smaller than that in rats pretreated with the three peptidase inhibitors, indicating that any residual single peptidase could inactivate significant amounts of the [Leu5]enkephalin. The present data, together with those obtained from previous studies, clearly demonstrate that amastatin-, captopril-, and phosphoramidon-sensitive enzymes play important roles in the inactivation of short endogenous opioid
    [Show full text]
  • New Trends in the Development of Opioid Peptide Analogues As Advanced Remedies for Pain Relief
    Current Topics in Medicinal Chemistry 2004, 4, 19-38 19 New Trends in the Development of Opioid Peptide Analogues as Advanced Remedies for Pain Relief Luca Gentilucci* Dipartimento di Chimica “G. Ciamician”, via Selmi 2, Università degli Studi di Bologna, 40126- Bologna, Italy Abstract: The search for new peptides to be used as analgesics in place of morphine has been mainly directed to develop peptide analogues or peptidomimetics having higher biological stability and receptor selectivity. Indeed, most of the alkaloid opioid counterindications are due to the scarce stability and the contemporary activation of different receptor types. However, the development of several extremely stable and selective peptide ligands for the different opioid receptors, and the recent discovery of the m-receptor selective endomorphins, rendered this search less fundamental. In recent years, other opioid peptide properties have been investigated in the search for new pharmacological tools. The utility of a drug depends on its ability to reach appropriate receptors at the target tissue and to remain metabolically stable in order to produce the desired effect. This review deals with the recent investigations on peptide bioavailability, in particular barrier penetration and resistance against enzymatic degradation; with the development of peptides having activity at different receptors; with chimeric peptides, with propeptides, and with non-conventional peptides, lacking basic pharmacophoric features. Key Words. Opioid peptide analogues; opioid receptors; pain; antinociception; peptide stability; bioavailability. INTRODUCTION. OPIOID PEPTIDES, RECEPTORS, receptor interaction by structure-function studies of AND PAIN recombinant receptors and chimera receptors [7,8]. Experiments performed on mutant mice gave new The endogenous opioid peptides have been studied information about the mode of action of opioids, receptor extensively since their discovery aiming to develop effective heterogeneity and interactions [9].
    [Show full text]
  • Treating Autism Spectrum Disorder with Gluten-Free and Casein-Free Diet: the Underlying Microbio- Ta-Gut-Brain Axis Mechanisms
    Cieślińska A, et al., J Clin Immunol Immunother 2017, 3: 009 DOI: 10.24966/CIIT-8844/100009 HSOA Journal of Clinical Immunology and Immunotherapy Review Article Abbreviations Treating Autism Spectrum ASD - Autism Spectrum Disorder GI - Gastrointestinal Disorder with Gluten-free and HPA - Hypothalamic-Pituitary-Adrenal Casein-free Diet: The underly- Introduction A growing number of children are diagnosed with Autism Spec- ing Microbiota-Gut-Brain Axis trum Disorder (ASD), a category of neuro developmental disorders Mechanisms such as Autism, Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) and Asperger’s disorder, collectively included 1 1 2* Anna Cieślińska , Elżbieta Kostyra and Huub FJ Savelkoul in the DSM-V criteria. The American Psychiatric Association’s Diag- 1Department of Biology and Biotechnology, University of Warmia and nostic and Statistical Manual, Fifth Edition (DSM-5) provides stan- Mazury, Olsztyn, Poland dardized criteria to help diagnose ASD [1]. The prevalence of ASD is 2Department of Cell Biology and Immunology group, Wageningen Universi- at least 1 in 160 children worldwide [2-4]. ty & Research, Wageningen, The Netherlands It is called a spectrum disorder because patients show a varying degree and severity of symptoms [1]. The most typical symptoms are deficits in social communication and interaction, along with restrict- ed interests, repetitive behaviors and a difficulty with imagination. Often, people with ASD avoid making eye contact with others, seem unresponsive to environmental cues and have difficulty to judge other people’s emotions [5-7]. Reduced pain sensitivity is often described as well [8]. The parents can often recognize these symptoms already Abstract at one year of age.
    [Show full text]
  • Structural Basis for Multifunctional Roles of Mammalian Aminopeptidase N
    Structural basis for multifunctional roles of mammalian aminopeptidase N Lang Chen, Yi-Lun Lin, Guiqing Peng, and Fang Li1 Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455 Edited by Ralph S. Baric, University of North Carolina, Chapel Hill, NC, and accepted by the Editorial Board September 21, 2012 (received for review June 13, 2012) Mammalian aminopeptidase N (APN) plays multifunctional roles in sensation and mood regulation by catalyzing the metabolism of many physiological processes, including peptide metabolism, cell neuropeptides that process sensory information. One of these motility and adhesion, and coronavirus entry. Here we determined neuropeptides is enkephalin, which binds to opioid receptors and crystal structures of porcine APN at 1.85 Å resolution and its com- has pain-relief and mood-regulating effects (9). APN degrades plexes with a peptide substrate and a variety of inhibitors. APN is and shortens the in vivo life of enkephalin, and hence enhances a cell surface-anchored and seahorse-shaped zinc-aminopeptidase pain sensation and regulates mood. Second, APN is involved in that forms head-to-head dimers. Captured in a catalytically active blood pressure regulation. APN degrades vasoconstrictive peptide state, these structures of APN illustrate a detailed catalytic mech- angiotensin-III, causing vasodilation and lowered blood pressure anism for its aminopeptidase activity. The active site and peptide- (10). An endogenous APN inhibitor, substance P, blocks both binding channel of APN reside in cavities with wide openings, the enkephalin-dependent and angiotensin-dependent pathways allowing easy access to peptides. The cavities can potentially open (11, 12). Third, APN is overexpressed on the cell surfaces of up further to bind the exposed N terminus of proteins.
    [Show full text]